Nonrecoil gun



May 2, 939- G, w L. PRET-TYMAN 2,156,605

NONRECOIL GUN Original Filed sept. 17. 1934 Snnentor @607:96 WLre@ man, Bg U.. q.

Patented May 2, 1939 Y UNgirar). 'sT-Ares NONRECOIL GUN George William Lyman Prettyman,`

Arlington, YVa.

Applieation september 17, 1934,- serial Nb. maisff Renewed. September 24, 1938 l1l Claim.

The present invention relates to improvements in the non-recoil gun ,so as to vgreatly enlarge its usefulness. The non-recoil gun has beenlieretofore restricted inits use bythe necessityfor 5 having a large zonefto the rear vwherein .the

rearward products of the explosion may be safelydissipated. v A further objectof the inventionlis to secure'the same result as above stated by the vuse of divided countercharges `and counter-masses. such counter-,charges being tired simultaneously or `,successively for the 'purpose of neutralizing the recoil of the gun whereby it will not disturb the balance of the aircraft on which'it is mounted. l5 `It is 'a further object of the invention to provide a gun of this character in which the rear blast is light enough to permit of the use of the gun by troops on the ground with but little danger. i, With the foregoing and other objects in view.

the invention will be more fullydescribed hereinafter, and will be'more particularly'pointed out in the claim appended hereto.

In the drawing, wherein like symbols refer to like or corresponding parts throughout the several views,

Figure 1 is a side elevation of an improved firing tube constructed according to the present invention. Figure 2 is a longitudinal section taken through the same.

Figure 3 is afcrss section taken von the line 3 3 in Figure 2.

Figure 4 is a similar view taken on the line 4 4, also in Figure 2, and

Figure 5 is a transverse section taken on the line 5 5 in Figure 2.

Referring more particularly to the drawing, 6 represents the firing tube preferably made of as thin a wall as practicable to sustain the explosive shocks to which a gun of this character maybe subjected. vThe tube will also be of a length shorter than .those found necessary owing to the improved counter-charge and countermassconstruction and arrangement. The projectile is indicated at I and the main propelling charge of powder at 8. A primer tube 9 lled with black powder dll extends at its front portion into the. main propelling charge 8. An intermediate perforated portion II of the tube 9 communicates with a second powder charge I2, while the rear end of the tube connects with a third powder charge I3. Two or more such powder charges may be provided. In the case of one additional powder charge over the propelling charge 8, the tube Ilv maybe a plain tube devoid yof the `perforations IIits rear end simply communicating with the second powdercharge.; In the case of four powder charges, there will be two perforated portions II to communicate with the -two intermediate powder charges.v 'Ihese various powdercharges may benin any quantity or .volume desired. l As shownk inthe drawing,l

the mainy propellingg chargegreatly exceeds that of thetwo charges II and I3 which dimin. 10 ish in volume toward thebreech muzzle I4 which l is open in the samefrnanner asthe forwardmuzzle I5. f v Suitable wadding or spacing partitions I6 may be provided at oppositesides ofthe projectile l5 and the powder charges and between the. powder charges and the various counter-weights or masses which are made up,ffor instance, of the masses of sand indicated at Il; I8 and I9.. The ignition circuit to the primer is indicated at 20. 20

In ,the useof the device by closingthecircuit 20 the primer is set off firing the main propelling charge 8 which drives the projectile I out of the forward muzzle I5 of the tube. At the same timethis propelling charge 8 reacts against 25 the various counter-masses of'sand I'I, I8 and I9 and drives the latter out toward the breech muzzle I4. In other words the main explosion pushes the projectile 'l forward and the adjacent sand Il rearward. The secondary explosion, 30 created by the firing of the charge I2, either simultaneously with the firing of the main explosive charge 8 or previously thereto, resists the rearward motion of the sand Il. Thus the main explosion, being restricted to the rear, de- 35 velops a higher pressure which results in higher muzzle velocity for the projectile. The total effect to the rear is diminished in intensity because of the slowing -up of the main section Il of sand. The other explosions, such as that pro- 40 vided by the charge I3, act similarly with less eiTect. By providing progressive explosions a rocket eiect is secured but simultaneous or nearly simultaneous explosions have been found in practice to give good results. 4 4:,

By the use of the invention the non-recoil features are preserved, while the blast to the rear is materially reduced without sacrificing the forward muzzle velocity of the projectile, and in fact with the use of the invention a higher muzzle 50 velocity may be secured.

By the use of the proper amount of sand for the amount of powder and weight and type of the lead pellets, the eiect of the explosion resulting in tube motion may readily be s o balanced u Itis well-known that by balancing equal weights one to go forward and the other backward n explosion, such balancing will result in no motion of the tube containing the explosion. The-relatively small amount of sandused successfully as a counter-recoil is due to the flowing of the sand like a liquid under the explosion pressure so as t9A expand against the walls o! the tube and momentarily prevent the egress of gasespast the sand'. and so hold up the internal pressure until ithas performed its useful work in imparting the necessary velocity to the lead pellets. The load used in the tube 4for the friction counter-balance is two and one-half pounds. It the load used `is based on the counter-weight balance, the weight i is four pounds twoj'unces. an increase of sixty as indicated. Sand is preferable as it has a high coemcient o1 friction. Also the sand is a ilnely divided mass and by reason ot its form is calculated to exert great frictional counter-effect in the tube. The sand comes in contact with the walls of the tube and exerts a counter-frictional `eil'ect in obtaining non-recoil of the tube. Its

value is very great as by its use the harmful rear effect is much reduced and the total weight of the ammunition is reduced nearly one-half. The counter-friction type weighs only sixty per cent of the counter-weight type ammunition. When the charge is red without any counter-weight or counter-friction mass' the tube kicks forward with good speed and the i'rictional efi'ect of the sand will avoid the same.

In some cases it may be advisable to make the tube thinA and light in which case the tube may be wrapped with wire externally to reinforce and strengthen the same.

It will beobvious that various lchanges in the arcanos /Having thus described my invention what I yclaim and desire to secure by Letters Patent of the United States is:

A projecting device comprising a cylindrical container open from end to end and having a bore and a counter bore, a projectile in the bore of the container, a yfriction mass of comminuted material in said counter bore spaced from the projectile, a propellant powder charge between said projectile and counter mass, a second counter mass of comminuted friction material in the counter bore spaced from therrst mentioned counter mass and being of smaller volume than the first mentioned counter mass, a second propellant powder charge between the two counter masses and being of smaller volume than the first mentioned powder charge, a third counter mass oi comminuted friction material in the counter bore spaced from the second counter mass, a third powder charge between said second and third counter masses, a primer tube extending through the counter bore and through'the nrst and second counter masses and through the second propellant powder charge' with its open ends communicating with the ilrst and third propellant lpowder' charge, said tube having openings'l communicating with the second propellant pow der charge, a primer powder in said tube, and means for igniting said primer powder, the combined volume of the three counter masses being cil less weight than the projectilesaid counter mass material having a higher coemcient of Iriction'with the walls of the container than the coeillclentlof friction of the projectile with the walls of the container. GEORGE-WILLIAM LYMAN PRETTYMAN. 

